Putting an aftermarket radio in a 03 Saab 93

Has anyone done this? I bought this car last year and havent looked into changing the radio up. I'm not big on factory shit - it doesnt sound bad but i'd much rather have something that I pick out that has more power. I have never seen the type of set up this thing has. It has 2 screens/radio/6 disc unit that all seem to be related. Am I stuck with this thing? I mean - I guess I understand that for the right sum of money you can do anything - but without getting into obsene amounts of cash is this something do-able or are we looking at a pretty major job?

Here is a glimpse of what it looks like. The disc slots are at the bottom and the radio controls are that screen in the middle - it even seems to relate to the top screen at times.